Funding is requested to support the next meeting of the National Neurofibromatosis Foundation International Consortium for the Molecular and Cell Biology of NF1 and NF2 to be held June 4-7, 2000 at the Hotel Jerome in Aspen, Colorado. Beginning with the first meeting in 1985, these conferences have served as the catalysts for many of the fundamental discoveries that have contributed major insights into these important diseases of the nervous system. These meetings provide a regular forum to bring together basic researchers, geneticists, clinicians, and others familiar with NF1 and NF2 to share their latest research findings and experiences. NNFF Consortia have been instrumental in the rapid advances in the molecular understanding of NF1 and NF2, including the cloning of the responsible genes, establishment of diagnostic tests, exploration of protein function, development of animal models, and creation of a network of patients and clinicians to facilitate clinical trials. The 2000 Consortium meeting has been organized as an open meeting that will be advertised to the general scientific community. Each of six platform sessions will be chaired by an expert in the field. These sessions will include 2 invited speakers from the NF research community with the other presentations to be selected from submitted abstracts. Participation by junior investigators will be encouraged and the organizers anticipate, on basis of previous Consortium meetings, that a substantial percentage of the speakers will be young investigators. Speakers will be instructed to limit their presentations to approximately half of the allotted time, with the remainder dedicated to open discussion among all participants. In addition, longer talks by four keynote speakers who are leaders in scientific fields or emerging technologies that are directly relevant to NF research will be incorporated into some of the scientific sessions. Two poster sessions will also be held which will allow investigators to present abstracts that are not selected for one of the oral sessions. In addition to updating investigators working on NF1 and NF2 on the latest research developments, this meeting will help to identify critical gaps in our knowledge as well as strategies and collaborations to address them. An improved understanding of the molecular basis of NF1 and NF2 will play an essential role in developing improved therapies for the complications of these disorders and has broad implications to the fields of developmental neurobiology and cancer research.